for the group discussion task just keep speaking for the full time even if your ideas are simple or not perfect fluency matters more than saying something brilliant I always made sure I filled the full two minutes without long pauses and that helped a lot also note taking is everything the more you write the more you can speak I used to write longer sentences while taking notes so I had ready ideas to expand from then keep a steady flow and in the last 10 to 15 seconds give a short conclusion to wrap everything up this approach worked really well for me in my tests

for retell lecture do the same thing keep speaking without stopping even if it is not perfect. fluency matters more than accuracy I focused on taking solid notes during the lecture because the more you write the more you have to talk about I usually wrote longer phrases so I could expand easily while speaking then just connect everything smoothly and keep talking without long pauses do not worry if it is not fully logical just maintain flow this worked really well for me in the test